1. Field of the Invention
This invention relates to a sensor for non-invasive measurement of sound pressure and vibration on the human body.
2. Description of Prior Art
Such a sensor is known from the brochure "Kreislauf-kontrollem mit den Infraton-Pulsabnehmer" (System: Boucke-Brecht) describing a pulse pickup. This pickup (sensor) features a probe which is effective with respect to a special-type capacitive winding and winding core arranged in an enclosure. The core of the capacitor is surrounded by an internal rubber jacket incorporating an air cushion. The rubber jacket is enveloped by silver wire meshing which is, in turn, surrounded by an outer rubber jacket around its outer surface.
This sensor is an electrostatic transducer of high capacitance which can be attached by bindings or bandages to suitable parts of the human body as a pulse pickup.
Other known sensors, particularly those used in cardiac sound measurements, feature a probe in conjunction with a lever mechanism for transmitting the deflection of the probe to an mechanoelectrical transducer. Sensors of this kind are a disadvantage particularly because they are large and relatively heavy and thus incondusive to the condition of the patient where applied to the surface of the body,, therefore, making measurements possible practically only when the patient is resting This, in turn restricts the scope of application of said known sensors since dynamic measurements, for instance when the patient is moving, are almost impossible or only with considerable impedance to the person concerned.